Pedal circuit for electronic organ



United States Patent 3,155,7o 0 Thomas et al.

inventors Appl. No.

Filed Patented Assignee John W. Robinson;

Richard M. Hereisen, Jasper, Indiana 736,652

June 13, 1968 Oct. 27, 1970 Jasper Electronic Mfg. Corporation Jasper, Indiana a corporation of Indiana PEDAL CIRCUIT FOR ELECTRONIC ORGAN K E YING VOLTAGE Primary ExaminerHerman Karl Saalbach Assistant Examiner-Tim Vezeau Attorney-Melvin A. Crosby ABSTRACT: Pedal circuit for electronic organ in which tone generators are provided for each scale note and each generator feeds a series of frequency dividers connected in cascade and in which one and the same frequency divider unit is utilized for all of the notes played by the pedal clavier of the organ.. Each pedal operates a switch to connect the pedal note frequency divider unit with a respective one of the cascaded frequency dividers pertaining to the respective note being played while a control switch is also actuated by the pedal for connecting the,pedal note frequency divider unit output with a transducer.

4O 0/ E02 3 C 4 OFF +I8V f w w it Patented Oct. 27, 1970 Sheet of 2 NM 9 vm Q m um N wN vN rmw N om IN-VENTOR. JQHN W. ROBINSON BYRIcHARo M. HEBEISEN PEDAL CIRCUIT FOR ELECTRONIC ORGAN This invention relates to electronic organs and the like and is particularly concerned with a novel frequency divider arrangement for use with an electronic organ for producing pedal tones.

The usual electronic organ has an oscillator for each of the twelve half steps of the chromatic scale and each oscillator supplies a group of frequency dividers connected in series so that from each oscillator there is derived a plurality of frequencies with the frequencies pertaining to any given oscillator being related as octaves. These frequencies, in an electronic organ, are generally referred to in relation to the length of a pipe organ pipe which will produce a sound of about the same pitch. Thus, the voltage dividers pertaining to each oscillator will normally provide for tones corresponding to 1 foot, 2 foot, 4 foot, 8 foot, 16 foot and, sometimes 32 foot pipes.

The usual electronic organ comprises upper and lower manuals and a pedal clavier. The upper and lower manuals utilize, in the main, tones corresponding to l, 2 and 4, and sometimes, 8 foot pipes. It will be understood that the manuals could extend to the longer pipes, but, for the purpose of the present application, it will be considered that the manuals use the tones corresponding to the 1 foot to 4 foot pipes and the pedal claviers use tones corresponding to 8 foot and I6 foot pipes. ln any case, it is customary for each half note to have an entire series of frequency dividers providing an entire range of notes from the high pitched note corresponding to 1 foot pipe down to the low pitched note corresponding to the 16 foot or 32 foot pipe.

While the keys in the two manuals of the organ may be, and usually are, depressed in a variety of combinations, the pedals are ordinarily depressed one at a time. Based on the proposition that the pedals are used only one at a time, the present invention proposesto use one and the same set of frequency dividers for all of the pedals of the organ rather than to use a separate set of frequency dividers for each half tone in the diatonic scale to supply the several pedals.

Accordingly, it will be understood that a primary objective of the present invention is the provision of an apparatus whereby one and the same frequency dividers can be used in an electronic organ for all of the pedal notes played by the pedals of the pedal clavier.

A still further object of this invention'is the provision of an apparatus for using one and the same set of frequency dividers for all of the pedal notes of the organ wherein thepedal notes sounded are distinct from each other and the sounding ofone pedal note, even when the note is sustained, does not interfere with the sounding of the next pedal note.

Another object'of the present invention is the provision of an electronic organ circuit which, through'the use of one and the same set of frequency dividers for all of the pedal notes, is more inexpensive than other types of electronic organ circuits.

, BRIEF SUMMARY OF THE INVENTlON The present invention provides, in combination with the pedals of the pedal clavier of an electronic organ, respective switching arrangements for the several pedals which-connect a source of frequency corresponding to the actuated pedal to the input of a set of frequency dividers and which frequency dividers, in turn, supply outputsthrough other switching arrangements to busamplifiers which supply the amplified outputs to the remainder of the organ circuitry, namely, to voicing circuits, amplifiers and speaker.

According to the present invention, one and the same frequency dividers are employed for all pedal notes so that, instead of twelve sets of frequency dividers, corresponding to Y the 12 half steps of the chromatic scale, only a single set of frequency dividers for the pedal notes is required.

The nature of the present invention and the several objects and advantages referred to above as well as still other objects and advantages thereof will become more apparent upon reference to the following detailed specification taken in connection with the accompanying drawings-in which:

FIG. 1 is a somewhat schematic block diagram which illustrates the principle of the present invention, and;

FIG. 2 is a somewhat more detailed representation of the portion of the organ circuit to which the present invention pertains.

Referring first to FIG. 1, switches operated by pedals of the pedal clavier of the organ are indicated at 10, 12, and 14. The blades of the switches are normally in the position in which they are illustrated in the drawing and are moved downwardly when a pertaining pedal is actuated so as to close on the respective lower contacts thereof, indicated at 10a, 12a, and 144 respectively. At this point it will be noted that the supply of negative keying voltage at point 16 is connected through a resistor 18 with the several switches l0, l2, and 14 in series so that actuation of any one thereof will interrupt the supply of keying voltage to those disposed farther away from the source of keying voltage.

Each contact 10a, 12a, 14a is connected to a terminal K of a pedal keyer 10b, 12b, and 14b respectively. Each keyer has an input terminal I which is connected to a respective source of frequency 10c, 12c, and 14c. The frequency supplied to terminals 10c, 12c, and 140 is in the form of a square wave from a frequency divider pertaining to the note to which the respective keyer pertains. For example, terminal might correspond to the note of C, terminal might correspond to the note B, while terminal 14c might correspond to the note A- sharp. .Each of the frequencies supplied to the terminals 100, 12c, and is preferably in the form of a square wave of a frequency corresponding to the respective note.

As has been mentioned before, these frequency inputs might be supplied from the outputs of the 4 foot dividers. Each of the pedal keyers has an output terminal marked 0 and these are all connected together and supply the input side of a pulse shaper 16. The output side of the pulse shaper triggers a first divider stage 19 and this divider, in turn. has a terminal connected by a wire 20 so as to trigger a following frequency divider 22. Assuming that divider 19 is triggered by a square wave corresponding to the output of a 4 foot pipe, the output from frequency divider 19, supplied to a wire 24 will correspond to an 8 foot pipe. Similarly, the frequency supplied by frequency divider 22 to a wire 26 will correspond to a l6 foot pipe. Wires 24 and 26 are connected to respective inputs ll and [2 of an audio keyer 28 which has an output 01 .cor' responding to the 8 foot pipes and an output 02 corresponding to the 16 foot pipes.

Audio keyer 28 has a control terminal C connected via a resistance 30.and diodes D4, D9, and D14 with the wires 10d 12d, and 14d, respectively leading from the terminals 10a. 12a, and 140 respectively. Between the points of connection of diodes D4, D9, andzDl4 with the aforementioned wires and the terminals K, are disposed of diodes D5, D10, and D15, respectively, with all of the diodes being poled in the direction toward the contactslfla 12a, and 14a.

The audio keyer 28 also has a sustain terminal S which is connected with a blade 32 of a sustain switch which is closab le on respective on and off terminals 34 and 36. Terminal 34 is not connected to any source of voltage whereas terminal 36 is connected to a source of plus 18 volts. When blade 32 is closed on terminal 36 the outputs at 01 and 02 are not sustained whereas when blade 32 is closed on terminal 34 these outputs are sustained.

In operation, when a pedal switch is closed, say, switch 10, a pulse is supplied to terminal K which opens pedal keyer 10b. A square wave at a predetermined frequency is supplied to terminal 1 and will now pass to terminal 0 and therefrom to pulse shaper 16 and then to frequency divider 19 which, in turn, will supply frequency divider 22. Outputs at predetermined frequencies will be supplied from dividers 19 and 22 to both wires 24 and 26 and thus to terminals I1 and 12 of the audio keyer 28. The frequency at terminal 12 will be one octave lower then the frequency at terminal 11 and the frequency at terminal 11 will be one octave lower than the frequency supplied to terminal 10c.

' Closing of the switch by depressing the pedal corresponding thereto will also supply a pulse to terminal C of the audio keyer 28 so that the input terminals 11 and 12 will pass to output terminals 01 and 02. These frequencies are supplied to the 8 foot and 16 foot busses at 38 and 40 respectively and from which busses the frequencies will be delivered to selected voice cards and the like and finally to the organ speaker means. I 7.

Each pedal keyeris arranged to remain open for a short period of time, say, 5 seconds after the pedal switch connected thereto is released. This is done for the purpose of maintaining the supply to the frequency dividers 19 and 22 so that when the sustain'switch blade 32 is in ON position, there will be a continuing supply to inputs [1 and 12 of the audio keyer throughout the sustain period. The maximum sustain period is about a second and a half and it will be evident that the possibility presents itself that a second pedal note might occur during this one and a half second interval.

The present invention takes this into account by providing a sustain cutoff at 42 which receives a pulse via condenser 44 each time a pedal switch is closed. The output from sustain cutoff 42 is supplied to the several terminals 51 of the pedal keyers and interrupts any outputs from the pedal keyers then existing thereby to interrupt the supply to frequency dividers 19 and 22 thereby to terminate the supply to input'terrninals Y l1 and 12 of the audio keyer 28. In this manner the pedal tones are prevented from undesirable overlapping of each other if I played at closer intervals than the duration of the sustain I period. v

The pulse supplied to terminals 100. 12c. and 14c is represented by the wave form indicated at 46. It will be understood that each of the terminals 100, 12c, and Mr: receives a wave form of slightly different frequency. The wave form of the pulse supplied via condenser 44 to the sustain cutoff 42 is indicated at 48 The output from the sustain cutoff is indicated by the short rectangular wave form at 50.

The outputs from the terminals 0 of the pedal keyers is represented by the square wave form at 52. it being un-" derstood that each terminal 0 of the pedalkeyers supplies a-- square wave like wave 52 but at a slightly different frequency.

The pulse shaper 16 supplies a wave form as indicated at 54' and which is the same as wave form 52 but preferably somewhat amplified and squared.

Frequency divider 19 supplies a wave form to wire 20 and 24 as indicated at 56 which is half the frequency of wave 54 and thus half the frequency of waves 52 and 46. Frequency divider 22 supplies to wire 26 a wave form 58 which is half the frequency of wave 56.

The pulse supplied to the audio keyer 28 is indicated by the wave at 60 with the side at 62 representing the voltage change that occurs upon the closing of a pedal switch and the side at 64 representing what occurs upon the releasing of a pedal switch.

Turning now to the more detailed diagram of FIG. 2, 13 pedal switches are shown and extend from a high C switch in half steps down to a low C switch. lt will be understood that p the designation high C and low C merely indicated that the high C is an octave higher than the low C and does not indicate that the tones are necessarily high or low. As a matter of fact, since the notes controlled by the switches are to be of 8 and 16 foot quality all thereof will be relatively low. The several switches referred to are connected, in the same manner as shown in FIG. 1 in series so that the actuation of any one will interrupt the supply to all of the others thereon the opposite side thereof from the keying voltage source.

The line 100 connected to the several pedal keys is connected to a minus 12 volt supply at 102 and is then connected through a resistor 104 and a resistor 106 with a minus 18 volt supply at 108.

From a point between resistors 106 and 108 there is a branch leading to ground and consisting of a resistor 110 and a capacitor 112 connected in parallel. There is also connected between resistors 104 and 106 a line leading through resistor emitter of which is connected through a capacitor 116 to ground and also through a resistor 118 to a plus 18 volt supply at 120. The emitter of transistor O3 is also connected to ground through a resistor 122 and is furthermore connected to the emitter of another transistor 01.

The collector of transmitter O3 is connected through a resistor 124 with the base of transistor Q1 and the base of O1 is furthermore connected through resistor 126 with the line leading to the emitter of transistor Q3.

The base of transistor Q3 is connected to ground via a capacitor 126 and is alsoconnected via a resistor 128 with a point between resistors 104 and 106. The base of transistor Q3 is also connected through a resistor 130 and acapacitor 132 in series with the resistor with wire 100. v

The keying circuits pertaining to the several pedal switches are identical and onlythat one pertaining to the high C pedal switch will be described in detail. At the bottom of FIG. 2

toward the left is a blockmarked SC which is the oscillator which produces the supply for all of the C notes of the organ for both manual keyboards and for the pedal clavier. Oscillator SC supplies a 1 foot frequency divider 134"'whi'ch in-turn supplies a 2 foot frequency divider 136 which in turn supplies a 4 foot frequency divider 138. Frequency divider 138 supplies wire 140 which corresponds to terminal 0 of the pedal keyer l0bofFIGQ1.

. Each frequency divider has a respective output wire 134a, 136a and 138d. Merely to illustrate the manner in which the outputs ofthe'frequency; dividers" are employed, it will be noted that wire 138a leads through a normally nonconductive keyer 142 which can be made conducti ve upon depressing of the manual key 144 pertaining thereto. Whenkey 144 is depressed and keyer 142 is conductive the output supplied to wire 1380 by frequency divider 138 is supplied to an amplifier 146 and then to a pertaining bus 148. Bus 148 is adapted for connection with voice cards such as 150. 152, and 154 by closing of the tab switches pertaining thereto which are in dicated at 156, 158 and. 160 respectively. When one or more of the tabswitches are closed. the frequency supplied to bus 148 passes through the voice cards pertaining to the closed tab switches and the frequencies are modified and shaped to produce the desired sounds and the outputs of the voice cards are then supplied through an amplifier 162 to a speaker means 164. It will be understood that the foregoing explanation and the showing of the circuitryis necessarily extremely simplified and is introduced merely for the purpose of making the disclosure herein somewhat more comprehensive.

Returning now to the pedal keyer pertaining to the high C switch, that portion of the pedal keyer which corresponds to the pedal keyer identified at 10b is enclosed in a dotted outline. Within the pedal keyer, commencing at the bottom with wire 140 is a first diode D1 and following the diode is a resistor R1 and continuing on upwardly is another resistor R3 which is connected to a point corresponding to terminal K of the pedal keyer 10b in FIG. 1. Point K is connected through diode D5 with the terminal 166 upon which the blade of the pedal switch corresponding to high C closes when the pertaining pedal is depressed.

inside the keyer the end of resistor R3 adjacent terminal K is connected to a' point 168 which is, in turn, connected through a capacitor C1 to a wire 170 that leads to the emitter of transistor Q1. Point 168 is also connected through a diode D3 with a wire 172 which is connected with the collector of transistor Q1. Diode D3 is poled in the direction from wire 172 toward point 168. The wires 170 and 172 are common to all of the keyers of the pedal clavier as shown. It will be understood that there could be more pedals if so desired and that all of the switches and keyers pertaining thereto would be connected in the manner illustrated.

The output terminals 0 of the pedal keyers of FIG. 1 is represented by the wire 174 in FIG. 2 which is common to all of the keyers. Wire 174, with reference to the particular pedal keyer being described, is connected through a diode D2 and a resistance R2 with a point between resistors R1 and R3.

The pedal keyer just described, and pertaining to the pedal switch marked high C,'is formed by the following components which have been described: D1, R1, D2, R2, R3, D3, C1, D5; and D4.

When the switch pertaining to the high C pedal is closed, a pulse will be supplied from the minus 18 volts source at 108 via a resistance 106 and a resistance 104 to wire 102 through the switch and through diode D4 pertaining to the high C pedal switch and also through D5. Resistor 104 will develop a pulse which is supplied to the base of transistor Q3 which will cutoff Q3 which, in turn, will cause transistor Q1 to go to saturation. When transistor'Ql goes to saturation, wire 170 is connected to wire 172 via the collector emitter circuit of Q1, and this permits all of the capacitors corresponding to capacitor C1 of the keyer pertaining to the'high C switch to discharge through their respective diodes, wires 170 and 172 and transistor Q1. During this time, capacitor 126 serves as a noise filter and the other components in circuit with transistors Q1 and Q3 establish that transistor 01 will be in saturation for about 20 milliseconds. which is ample time for all of the aforementioned capacitors to discharge. The capacitors just referred to include the capacitors numberedfrom C1 to C13 in FIG. 2. The circuitry consisting of transistors'Ql and Q3.

having the components connected thereto, corresponds to the sustain cutoff 42 of FIG. 1.

The pulse shaper 16 in FIG. 1 is represented by the transistors Q9 and Q10 in FIG. 2. The base of Q10 is connected through a capacitor C withthe common output wire 174 of the several keyers. Wire 174 is also connected to ground through a resistor R74. The base of transistor Q10 is also connected through a resistor R72 with a minus 15 volts supply at 180. The base of transistor O1 is furthermore connected through a resistor R75 to ground and in parallel with R75 is a branch comprising a capacitor C16 and resistors R76 and R77. Resistor R77 is bypassed by capacitor C18. The junction of capacitor C16 with resistor R76 is connected to the emitter of transistor Q10. The collector of Q10 is connected through a resistor R73 with the wire leading to a minus 15 voltage source at 180 and is also connected through a capacitor C17 with ground. The collector of transistor Q10 is furthermore connected through a resistor R71 with one side of the capacitor C19, the other side of which is connected through a resistor R70 with ground and also to the base of transistor Q9. The emitter of transistor O9 is grounded whereas the collector thereof is connected through a resistor R42 with a minus 5 volt supply at 182. The collector of transistor O9 is also connected with the trigger or input terminal T of a first frequency divider pack 184 which has leading therefrom a wire 186 to which is supplied a wave of half the frequency of the wave which is supplied to the input terminal T.

The frequency divider includes terminal 188 connected to a minus 4.2 volt supply at 191, a terminal 190 connected to a wire 186 and also to a collector of a transistor Q5 and has further terminal 192 connected to the base of a transistor 06.

9 Still another terminal 194 is connected with a plus 5.5 volt supply at 196. Another terminal 198 is connected with the base of transistor Q5 and a final terminal 200 is connected with the collector of the aforementioned transistor Q6.

The emitters of transistors Q5 and 06 are connected together and via the resistor R44 with a plus 3.2 volt supply at 202. The collector of transistor 06 is connected to the input terminal T1 of a second frequency divider 204 and triggers the said second frequency divider. The two frequency dividers are the same and are connected in the same way except that the output wire 206 leading from frequency divider pack 204 has half the frequency of the output supplied to wire 186 by frequency divider pack 184. The outputs of 186 and 206 are thus an octave apart and the wire 186 supplies 8 foot tones and wire 206 supplies 16 foot tones.

The input to frequency divider pack 204 is derived from frequency divider pack 184 and theinput to frequency divider pack 184 is derived from the pulse shaper consisting of the transistors Q9 and Q10 which, in turn, is supplied by wire 174 which forms the common output for the several pedal keyers referred to.

The audiokeyer 28 referred to in FIG. 1 is supplied by the wires 186 and 206 and is connected to be keyed in response to pulses in wire and is connected to supply respective 8 foot and 16 foot amplifiers which, in turn, supply voicing circuits and therefrom supply amplifier means andspeaker means.

Considering first, wire 186, this is connected through a diode D68 and a resistor R64 to a point 208. From point 208 the circuit continues through a resistor R61 and diode D70 to a point 210 which is connected through a resistor R60 to ground and is also connected to the base of an amplifying transistor Q4 and also through a resistor R66 with a wire leading to the minus 15 volt supply at 180. Diodes D68 and.D70 are poled toward each other.

Point 208 is connected through the parallel arranged resistor R69 and capacitor C21 with a point 212 which is connected with the end of resistor 171 where'it joins resistor 173. This same point is .connected through a capacitor C14 to ground and-is also connected through a resistor R41 and a diode D66 with the OFF terminal 214 of the sustain switch. The sustain switch includes a blade 216 connected to a plus 1 8 volt supply 218 and blade 216 is selectively movable into engagement with the OFF terminal 214 or with the unconnected ON terminal 220.

Wire 206 isconnected in the same manner through a diode D67 and a resistor R65 to a point 222 that corresponds to the aforementioned point 208 pertaining to wire 186. Point 222 is connected through the parallel arranged resistor R43 and capacitor C20 with point 212. Point 222 is also connected through resistor R45 and diode D69 with the base of the 16 foot amplifier transistor Q2. the said base furthermore being connected through a resistor R63 to ground and through a resistorR62 to the wire leading to the minus l5 volt supply at 180.

The collectors of transistors Q2 and 04 are connected through resistors R59 and R67 respectively with the wire leading to the minus 15 volt supply at Each of the collectors of the transistors Q2 and 04 are connected to respective busses and, in order to clarify the disclosure. the collector of transistor O2 is shown connected to a lo foot bus 224 that is connected to one side of the tab switches 226, 228, and 230 to which pertain therespective voice cards 232. 234, and 236. The output sides of the voice cards are connected to the input side of an amplifier 238 the output side of which is connected to the speaker means 240. The voice cards 232. 234. and 236 are provided just for the 16 foot pedal notes but amplifier 238 and speaker means 204 can be the same as amplifier means 162 and speaker means 164 previously described as receiving the output from the manual keys. The collector of transistor Q4 corresponding to the 8 foot pedal notes is connected to an 8 foot bus, not shown, and then through respective tab switches and voice cards with amplifier 238 and speaker means 240.

When a pedal note switch is closed, as mentioned above, for example, the high C pedal, to close its blade on terminal 166, a signal commences to be supplied from wire 140 to wire 174 and through the pulse shaper consisting of transistors Q9 and Q10 to frequency divider 184 and from which frequency divider'204 is triggered. Thus, a very short time after closing the high C pedal switch frequencies are supplied to wires 186 and 206.

When the pedal switch is closed there is also a pulse developed by means of which capacitor C14 triggers the audio keyersinto conduction. This occurs just after the frequency dividers 182 and 204 become operative. a matter of only a few milliseconds at most, andthese frequencies are thus conveyed to transistors Q2 and Q4 and therefrom are supplied to the respective 8 and 16 foot busses.

Diodes D4 and D5 isolate the keying voltage for the pedal keyer from the audio keyer so that there is normal sustain in respect of the audio keyer. The audio keying voltage is supplied thereto from resistor 173 and the audio keyer proper can be considered to be made up of the capacitor C14, the resistor 171, the resistor R41, diode D66, diode D70, resistor R61, resistor R64, diode D68, resistor R69, capacitor C21, resistor R43, capacitor C20, diode D67, resistor R65, diode D69 and resistor R45. Resistor R41 and diode D66 are, of course, effective only when switch blade 216 is closed on terminal 214 to eliminate a sustain action.

With respect to the pulse shaper consisting of transistors Q9 and OM and the circuit components connected thereto, transistor Q10 acts as a linear amplifier with capacitors C17 and C16 serving to filter out noise. Transistor Q9 effects the actual shaping of the pulse to feed the divider string consisting of the divider packs 184 and 204, transistors 05, Q6, Q7 and Q8 and resistors R44 and R68.

As mentioned before, the frequency dividers supply the 8 and 16 foot amplifiers via the audio keyer, and said amplifiers consisting of transistors Q4 and Q2 and resistors R66, R67,

' R54, R60, R62, R59, R58, and R63 associated therewith.

With respect to the pedal keyers, it will be seen that the plus 18 voltage source at 120 and the resistors 118 and l22form a bias network that holds the pedal keyers in OFF condition until a pedal switch is closed.

Resistors I06 and 110 and the capacitor 112 establish the keying voltage for operation of the pedal keyers.

Once a pedal keyer is actuated to open or conductive condition by closing of the pedal switch pertaining thereto, it will stay open for about 5 seconds after the pedal is released to insure that the frequency dividers 184 and 204 will be supplied the maximum duration that the pedal notes might be sustained. As mentioned, the maximum sustain time that will normally be built into the audiokeyer is about one and one half seconds so that the 5 second interval that the pedal keyers stay open after their switches are released is an adequate length of time.

It has also been mentioned that one pedal note may follow another so closely that the pedal keyer for the first note may still be open when the second note is played and this is taken care of by the sustain cutoff circuitry consisting of transistors Q1 and Q3 in the manner hereinbefore described, namely by discharging all of capacitors Cl and CB when transistor Ql goes conductive at the instant a pedal switch is closed. As mentioned, transistor 01 remains in saturation only about 20 milliseconds and this permits all of the capacitors Cl and C13 to discharge completely. The sustain cutoff circuitry thus closes any open pedal keyers when a pedal pertaining to another note is actuated.

With reference to the reference numerals on the drawings, it has been explained that the keying arrangement pertaining to the high C pedal switch is made up of the diodes D1, D2, D3, D4, and D5 and of the resistors R1, R2, R3, and of the capacitor C 1.

The pedal keyer for the note B corresponds to the pedal keyer for high C note is made up of the same components, but the components have been consecutively numbered. This system of numbering is followed throughout FIG. 2 for the remainder of the pedal keyers.

Modifications may be made within the scope of the appended claims.

We claim:

1. ln an electronic organ having manually operable keys and a pedal clavier, an oscillator pertaining to each note of the chromatic scale, a set of frequency dividers arranged in series for each oscillator, each set of frequency dividers having an input terminal supplied by the respective oscillator and also having a plurality of output terminals at which frequencies related as octaves are developed and which correspond to the notes of the manually operable keys, further frequency divider means having output means and having an input terminal, a normally nonconductive pedal switch means connected between said input terminal of said further frequency divider means and a respective lower frequency output terminal of each said set of frequency dividers, each said pedal switch means being operated into conductive condition by the actuation of a peda of the pedal clavier which corresponds to the oscillator supplying the pertaining set of frequency dividers, transducer means to which the output means of said further frequency divider means is supplied to convert it to sound, a normally nonconductive further switch means between the output means of said further frequency divider means and said transducer means, means operable in response to the actuation of a pedal of the pedal clavier for making said further switch means conductive, and means for delaying for a predetermined time the response of said further switch means to the actuation of a pedal so that firstly the respective said pedal switch means becomes conductive to initiate a supply to said further frequency divider means and thereafter said further switch means become conductive to connect the out put means of said further frequency divider means to said transducer means.

- 2. The arrangement according to claim 1, which includes a capacitor in circuit with each pedal switch means and a source of charging voltage connected to each capacitor, said source of charging voltage charging each capacitor to a level less than that required to make the respective pedal switch means conductive but sufficient to hold the respective pedal switch means in conductive condition for a predetermined length of time following release of the respective pedal.

3. The arrangement according to claim 2, in which all of said capacitors having one terminal connected to a first wire via a diode and the other terminal connected to a second wire, a transistor having its collector-emitter circuit connected across said first and second wires and its base biased so the collector-emitter circuit is nonconductive, and means responsive to the actuation of a pedal of the pedal clavier for supplying a pulse to said base to make said collector-emitter circuit momentarily conductive so as to discharge said capacitors at the instant of actuation of a pedal.

4. The arrangement according to claim 3, in which said transducer means comprises serially arranged voicing circuits and speaker means, and means for making said voicing circuits selectively effective and ineffective.

5. The arrangement according to claim 4, in which said further switch means comprises an audio switch for each of the output terminals of the frequency dividers of said further frequency divider means, said audio switches having a common control terminal connected to receive signals from said pedal switch means, an amplifier following each audio switch, said voicing circuits comprising voicing circuits in series with each amplifier, and said speaker means being common to said voicing circuit. 

